Abstract: As the application of blockchain in the internet of things scenario continues to gain popularity, it becomes increasingly difficult to meet the real-time transaction processing requirements of IoT devices, and the issue of low blockchain throughput becomes increasingly prominent. Existing solutions often rely on technologies such as blockchain sharding, block pipeline, and concurrency control to enhance throughput, but these solutions do not significantly improve throughput in some conflict scenarios. This paper analyzed the characteristics of smart contract transactions of hotspots and the applicable scenarios of various concurrency control technologies. Relying on blockchain sharding technology, it constructed shards for smart contracts of hotspots with high conflict rates and shards for ordinary contracts with low conflict rates. It adapted corresponding concurrency control technologies for the two types of shards, fully leveraging the advantages of each technology to ultimately achieve efficient multi-dimensional parallelism between shards and transactions. Additionally, this paper proposed a formula for evaluating the performance of trusted sensors, assigning adaptive data transmission tasks based on different sensor capabilities, thereby enhancing overall data transmission efficiency. Experimental results have demonstrated that the improvement of throughput of the proposed solution is significant. The solution improves performance more efficiently compared to other single-dimensional parallelism solutions.

Key words: blockchain, parallel execution, smart contract of hotspot, sharding, throughput, concurrency control